What Does a Structural Mechanic Do?

Structural mechanics is a branch of solid mechanics. It mainly studies the laws of force and transmission of engineering structures and how to optimize the structure. It is a compulsory subject for students majoring in civil engineering and mechanical engineering. The research content of structural mechanics includes the composition rules of the structure, the response of the structure under various effects (external forces, temperature effects, construction errors, and support deformation, etc.), including the internal forces (axial, shear, bending moment, torque). Calculation, displacement (linear displacement, angular displacement) calculation, and calculation of the dynamic response (natural vibration period, mode shape) of the structure under dynamic load. There are usually three analysis methods in structural mechanics: energy method, force method, displacement method, and matrix displacement method derived from displacement method. Later, the finite element method has been developed, which has become the theoretical basis for structural calculation using computers.

Structural mechanics is an ancient discipline and a rapidly developing discipline. The emergence of a large number of new engineering materials and new engineering structures has provided new research content and proposed new requirements for structural mechanics. The development of computers has provided powerful calculation tools for structural mechanics. On the other hand, structural mechanics has also promoted the development of mathematics and other disciplines. The emergence and development of the mathematical method of the finite element method is closely related to the study of structural mechanics. In the field of solid mechanics, material mechanics provides the necessary basic knowledge for structural mechanics. Elasticity and plasticity are the theoretical foundations of structural mechanics. In addition, the combination of structural mechanics and fluid mechanics forms a marginal discipline-structural fluid elastic mechanics.

From the perspective of mechanics, the strength and stiffness of the structure are mainly used to evaluate the strength and weakness of the structure. The design of the engineering structure must ensure that the structure has sufficient strength and that it has sufficient rigidity. Insufficient strength causes the structure to be easily destroyed; insufficient rigidity causes the structure to be easily wrinkled, or large vibrations may occur, or large deformation may occur. Wrinkles can cause deformation and damage to the structure. Vibration can shorten the service life of the structure. Wrinkles, vibration, and deformation will affect the performance of the structure, for example, reducing the machining accuracy of the machine tool or reducing the efficiency of the control system.

Observing the natural structures in nature, such as the roots, stems and leaves of plants, the bones of animals, and the shells of eggs, you can find that their strength and stiffness are not only related to materials, but also closely related to their shape. Many engineering structures are inspired by natural structures. Based on the study of structural mechanics, people have continuously created new structural shapes. Stiffening structure (see

Research engineering structure (so-called

Humans began to make various artifacts such as bows and arrows,

Generally speaking, structural mechanics can be divided into

The research methods of structural mechanics mainly include the use of engineering structure analysis, experimental research, theoretical analysis and calculation. In structural design and research, these three aspects are often carried out alternately and complement each other.

Use analysis In the process of using a structure, it is an easy and reliable method to analyze, compare and summarize the situations that occur in the structure. The use of analysis plays an important role in the evaluation and improvement of the structure. The newly designed structure also needs to be used to verify performance.

Experimental research can provide an important basis for identifying structures, which is also the main means for testing and developing structural mechanics theories and calculation methods. The experimental research is divided into three categories: model experiments: simplify the real structure or a part of it into a model, and then carry out afterburning experiments according to design or research requirements; real structural component experiments: it has two tasks, one is to verify the model The reliability of the simplified model used in the experiment. The second is to verify the accuracy of the theoretical design calculations. Real structure experiments: for example, aircraft ground damage experiments, flight experiments, and car driving experiments. (see

The principle of energy in structural mechanics expresses the relationship between stress, strain or deformation, displacement, material properties and external influences in the form of energy or operations of internal and external forces. Since energy is a scalar, these relationships provide convenient and alternative methods for governing equations of deformable bodies in solid mechanics. They can also be used to obtain approximate solutions for fairly complex systems, bypassing the difficult task of understanding a set of controlling partial differential equations. ^[6]